ovn-northd: Avoid null deref for missing outport in build_static_rout…

…e_flow().

Found by Coverity.

Reported-at: https://scan3.coverity.com/reports.htm#v16889/p10449/fileInstanceId=14763080&defectInstanceId=4305186&mergedDefectId=179788
Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Miguel Angel Ajo <majopela@redhat.com>

ovn/northd/ovn-northd.c

@@ -3255,7 +3255,7 @@ build_static_route_flow(struct hmap *lflows, struct ovn_datapath *od,
         }
     }
 
-     if (!lrp_addr_s) {
+    if (!out_port || !lrp_addr_s) {
         /* There is no matched out port. */
         static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 1);
         VLOG_WARN_RL(&rl, "No path for static route %s; next hop %s",